Crystal Structure,Electronic Structure,and Luminescence of Cs2KYF6:Pr3+

The crystal structure, electronic states and VUV spectroscopic behaviour of Cs₂KYF₆ doped with Pr³⁺ ions have been investigated both by experimental and theoretical methods. Cs₂KYF₆ ( , Z = 4, a = 945.5(3) pm, R1_all = 0.0297) crystallizes with the cubic elpasolite type of structure. The local relaxation of the activator ions in the host lattices has been calculated by the projector augmented wave method (computer code VASP). The electronic states have been calculated using a spin density functional procedure based on the atomic sphere approximation (computer code ASW). VUV spectroscopic measurements show fast 4f¹5d¹ → 4f² emission of nanosecond duration as well as slow 4f² → 4f² emission depending on the excitation energy which indicates the occupation of different sites in the host lattice. This assumption was verified by a recently developed quantum mechanical method. The combination of the experimental and the theoretical results show that the Pr³⁺ ions are occupying three different sites, namely the Y³⁺ and the Cs⁺ site as well as the K⁺ site.     

Condensation reaction in the bandpass reaction cell improves sensitivity for uranium,thorium, neodymium and praseodymium measurements

Condensation reactions in the bandpass reaction cell or dynamic reaction cell (DRC) were used for the determination of actinides and lanthanides such as uranium, thorium, neodymium and praseodymium. These elements react with oxygen reagent gas in the dynamic reaction cell of the ELAN DRC II instrument to give mono- and/or dioxo cationic species (UO₂⁺, ThO⁺, NdO⁺ and PrO⁺, respectively). Increasing the oxygen flow rate in the dynamic reaction cell leads to the rapid decrease of the singly charged metal ions accompanied by the fast increase in the intensity of the oxide ion. This phenomenon is used to improve considerably the sensitivity of ICP-MS instruments equipped with a dynamic reaction cell for actinides and lanthanides. Estimated detection limits (EDL) obtained in this work for uranium, thorium, neodymium-144 and praseodymium are 0.022, 1.0, 0.045, and 0.10 ng L^–1, respectively. The detection limit for uranium measured in the standard (vented) mode of an ELAN DRC II was found to be 0.22 ng L^–1, which is an order of magnitude higher compared to the pressurized mode.     

A complementary electrochromic system based on Prussian blue and indium hexacyanoferrate

A new complementary electrochromic device (ECD) based on Prussian blue (PB), indium hexacyanoferrate (InHCF), and KCl-saturated poly(2-acrylamido-2-methylpropanesulfonic acid) (K-PAMPS) was proposed and studied in this work. This novel PB-InHCF ECD (PIECD) exhibits blue-to-yellowish electrochromism with a high coloration efficiency of ca. 103 cm²/C at 690 nm. Although the operating voltages for the fully bleached and fully colored states were determined to be 1.2 V and 0 V (InHCF vs. PB), respectively, the major transmittance modulation occurs within a much narrower voltage window (0.9 V↔0.5 V). That is, the PIECD is energetically favorable. Furthermore, it is unnecessary to precolor either electrochromic (EC) electrode during the cell assembly so that the charge balance between two electrochromic films becomes much easier. In addition to the above performance, the compatibility between the K-PAMPS electrolyte and EC electrodes was also demonstrated. In short, this work proposes another promising PB-based ECD and provides a new choice in the EC field. Electronic Publication     

电化学石英晶体微天平研究六氰亚铁铜膜修饰电极及其离子效应

利用电化学石英晶体微天平（EQCM）手段，结合循环伏安法．计时电流法对六氰亚铁铜（CuHCF)膜修饰电极及其在不同水溶液中的离子交换机制进行了研究。结果表明；通过循环伏安法，在Pt电极上可以牢固地形成CuHCF膜．在氧化还原过程中，不仅是阳离子，阴离子也参与了在CuHCF膜中的传输。     

分光光度法测定氯化稀土和轻稀土氧化物中的镨,钕,钐

本文提出在１０％盐酸介质，用紫外－可见分光光度法测定氯化稀土、轻稀土氧化物中的镨、钕、钐，测定波长分别为４４４ｎｍ、５７５ｎｍ、４０１ｎｍ，钐对镨的干扰和镨对钕的干扰均可用校正系数加以消除。方法回收率为９７．５％～１０２．９％，检出下限分别为５０×１０￣（－６）ｇ／ｍＬ，１０×１０￣（－６）ｇ／ｍＬ，１００×１０￣（－６）ｇ／ｍＬ。     

Kristallstruktur von Tl4Fe(CN)6

Crystal Structure of Tl₄Fe(CN)₆ Single crystals of Tl₄Fe(CN)₆ have been prepared for the first time and its crystal structure was determined. The pale yellow compound crystallizes in the triclinic space group P1 (No. 2) with the lattice parameters a = 726.6(1) pm, b = 797.4(8) pm, c = 1 336.0(1) pm, α = 104.7(9)°, β = 90.0(8)°, γ = 97.6(7)°, Z = 2 in a new structure type.     

铁氰化钆修饰电极的固态电化学及电催化性能

制备了一种新的稀土铁氰化物——铁氰化钆(GdHCF), 并对其进行了表征. 元素分析、EDX和TGA结果表明, GdHCF的计量式为NaGdFe(CN)6•12H2O(在NaCl溶液中制备), 红外光谱结果显示GdHCF晶体中有两种形式的水分子存在, 一种是靠氢键结合的填隙水分子(5个), 一种是与Gd配位的配位水分子(7个)；XPS结果表明GdHCF中铁为+2价, 钆为+3价. 将GdHCF固定到石墨(SG)电极上(GdHCF/SG), 研究了它的固态电化学性能, 其循环伏安曲线上表现出一对良好且稳定的氧化还原峰, 式量电位E0′几乎不随扫速而变化(在10~300 mV•s−1范围内, E0′平均值为(197±3) mV)；并且E0′与支持电解质中阳离子(Na+)活度的对数(lgaNa+)之间呈线性关系, 斜率为54.1 mV, 这一特性关系可用于测定NaCl溶液中Na+的活度. 进一步研究的结果表明, GdHCF对神经递质多巴胺(DA)和抗坏血酸(AA)的电化学氧化均具有催化作用, 催化电流随DA(或AA)浓度的增加而增加.     

Pd/C: A Recyclable Catalyst for Cyanation of Aryl Halides with K4[Fe(CN)6]

Aryl nitriles have been prepared from the corresponding aryl halides with potassium hexacyanoferrate(II) using Pd/C as a catalyst. No ligand or cocatalyst is required. This protocol also avoids the use of highly toxic alkali cyanides. Furthermore, the catalyst can be recycled via simple filtration and washing sequences.     

Solvent-Free Synthesis of Arylsulfonyl Cyanides Using Potassium Hexacyanoferrate(II) as An Ecofriendly Cyanide Source

Abstract

A solvent-free synthetic method for arylsulfonyl cyanides directly from corresponding sulfonyl chlorides using potassium hexacyanoferrate(II) as an ecofriendly cyanide source is described. The protocol has the advantages of no uses of highly toxic cyanating agent and volatile organic solvents, high yield, and simple work-up procedures.     

Optical Amplification on the 3P0 3F2 Transition in Praseodymium-doped Fluorozirconate Fiber

Small-signal amplification on the 3P0 3F2 transition in a praseodymium-doped fluorozirconate optical fiber at the 632.8-nm He-Ne wavelength, has realized a slope efficiency of 0.15 dB mW and up to 14 dB gain. Spectroscopic and fiber parame ters, including the pump absorption cross section (sigma a 0.14 0.02 10 24 m2), p the signal emission cross section (sigma e 2.1 0.2 10 24 m2), and the 3P state ( ) s 0 lifetime tau 3 49.8 0.3 mus , determined experimentally, independently of the gain, were used to model the performance of the amplifier. The predictions of the rate equation model were in good agreement with the measured gain.